Staple-driving machine



J. MUTH.

STAPLE DRIVING MACHINE.

APPLICATION FILED MAR. 24. 1921.

1,397 176,, Pamemedl Nov. 15, 19216 ATTORNEY JOHN MUTE, OF NORWALK,CONNECTICUT, ASSIGNOR TO THE E. H. I-IO'ICHKISS COMPANY, OF NORWALK,CONNECTICUT, A CORPORATION OF CONNECTICUT.

STAPLE-DRIVING MACHINE.

Specification of Letters Patent.

Patented Nov. 115, 1921.

Application filed March 24 1921. Serial No. 455,123.

To all whom it may concern Be it known that I, JOHN MUTH, a citizen ofthe United States, residing at Norwalk, county of F airfield, State ofConnecticut, have invented an Improvement in Staple- Driving Machines,of which the following is a specification.

This invention relates to stapling machines, and more particularly tothat type known as strip staple machines, wherein each staple, at thetime it is driven.is severed from a strip of integrally connectedstaples which is fed forward at each operation of the machine to bringthe staples successively into aposition to be severed and driven.

The invention has for its general object the provision of a novelstapling machine of this general type which is of simple and inexpensiveconstruction, which is durable and not likely to get out of repair, andwhich is positive and reliable in its operation.

Another object of the invention is to provide, in a machine of thisgeneral type, simple and positive means .for rigidly holding. during thesevering operation, the prongs of each staple as it is severed from thestrip, thereby overcoming the tendency frequently encountered in the useof machines of this type on the part of the cutting and drivingmechanism, particularly when said mechanism ha become slightly dull. tobend the staples and wedge the same in the throat of the machine insteadof severing them cleanly and driving them straight through the throat inthe proper manner;

With the foregoing and other objects in view, I have devised the novelstapling machine which I will now describe, reference being had .to theaccompanying drawing forming a part of this specification and in which:

Figure 1 is a longitudinal vertical section of the complete machine,showing the interior parts in elevation.

Fig. 2 is a horizontal section of the forward part of the machine takensubstantially on the line 22, Fig. 1.

Fig. 3 is a perspective view, on an enlar ed scale, of one of the stapleholding members.

Fig. 4 is an enlarged plan view. and Fig. 5, an. enlarged side elevationof the feed pawl.

Fig. 6 is an enlarged horizontal section,

taken substantially on the line 66, Fig. 7, F

of the staple carrying bar, showing a modified construction.

Fig. 7 is a side elevationof the parts shown in Fig. 6.

Fig. 8 is a view similar to Fig. 23 of one of the staple holding membersshown in Figs. (3 and T. I

10 denotes the machine base. which is provided at its forward end withan anvil 48 having the usual concave clenching recess 11. Pivoted tosaid base is the head of the machine. which comprises a casing I) havingat its lower side a longitudinal recess ll in which is located a staplestrip carrying bar 15 upon which the staple strip slides. said bar beingsecured to the casing by pins 16. and being pivoted at 13 betweenupstanding ears 4.) at the rear end of the base 10. The bar 15 iscentrally located in the recess 1%. and the upper portion thereof isspaced from the lateral walls of said recess by plates 17 interposedbetween said bar and walls in order to provide the necessary clearancefor the tree passage of the staple strip 50. At its forward end. thecasing 12 is formed with a vertically disposed. ubstantially cylindricalguide 18 for vertically reciprocating plunger 19 having a knob or handpiece 20 at its upper end. A coil spring 21 is interposed between thehand piece 20 and the top of the guide 18. said spring normally holdingthe plunger in raised position. The flat forward end of the bar 15 isdisposed in substantial alincment, or in substantially the same verticalplane with the flat rear face of the plunger 19, only sufiicientclearance being provided between said bar and plunger to permit thelatter to pass the former and cooperate therewith to shear off the firststaple of the strip when the plunger is depressed. The staple strip issupported and slides on the top of the bar 15 with its foremost staplenormally projecting beyond the end of the bar in a position to besevered from the strip by the plunger 19 in its downward movement anddriven through the throat 22 of the machine upon the anvil 48.

23 denotes a cam plate pivoted at 25 within the casing 12 at the rear ofthe plunger 19.- 26 denotes a feed .pawl comprising a pair of arms 24lying at opposite sides of the cam plate 23 and pivoted thereto at 35.The upper edges of the rear ends of the arms26 are connected by a bridgepiece 27,-while their forward ends press at their lower sides upon thetop of the staple strip and are provided with downwardly inclinedbeveled teeth 28. The arms 24 straddle the continuous portion of thestaple Strip 50 and engage the upper portions of the individual staplesthereof, the beveled ends of the lugs 28 causing them to be wedgedbeneath said staples as the feed pawl is moved forwardly, therebypositively holding said pawl in engagement with the strip, preventingit' from riding idly thereover during its forward movement and insuringthe proper feeding of the staples. 29 denotes a plunger guided forlongitudinal movement in a horizontal recess 30 in the casing 12, saidplunger being yieldingly forced outwardly by a spring 34 in said recess,and engaging at itsforward end the bridge piece 27 of the pawl 26,thereby normally position with its forward end depressed against thestaple strip. The cam plate 23 is oscillated on its pivot 25 at eachreciprocation of the plunger 19 by a lug 31 on said plungerwhichengagesupper and lower cam surfaces 32 and 33 formed on said camplate, said cam surfaces being so designed that at each oscillation ofthe cam plate the feed pawl will'be moved a distance corresponding withthe width of one staple on the strip. When the plunger '19 is depressed,engagement of the lug 31 with the cam surface 33 causesthe feed pawl 26to be retracted or moved backward'ly upon the staple strip, and whensaid plunger is raised engagement of said lugwith the cam surface 32causes said feed pawl to be moved forwardly to advance the strip. Asindicated at 36, the cam plate 23 is slightly beveled at its lower end,and the forward ends of the arms 24* on the feed pawl 26 are bentslightly inwartlly toeengage the beveled portions of the plate, therebyholding said pawl against lateral movement and also preventing it frombeing raised too high, while permitting it to ride over the staple stripon its backward movement.

In machines of this type, as heretofore constructed, considerabletrouble has been caused by bending of the staples and wedging thereof inthe throat 22. After the machine has been in use for some time, thecooperating shearing edges on the front end of the bar 15 and onthelower end of the plunger 19 becomes dull, so that the plunger tends,casing bar 15, said dogs being; provided at their shoulders 41 holdingsaid pawl in its forward to bend the end staple around the edge of thebar instead of cutting itsquarely from the strip. In order to overcomethis difficulty and in accordance with} the present invention, thefollowing means are employed.

Referring to Figs. 2 and 3, 37 denotes dogs pivoted at 38 in slots 39 inthe sides of the 12 adjacent the forward end of the rear ends with leafsprings40 which engage the ends of said slots andtend to force theforward,ends of saiddogs inwardly, said. leaf springs being preferablyset in kerfs cut in the rear. ends of said dogs. The dogs 37 areprovided at their forward ends with stop which engage complementaryshoulders at the forward ends of the slots 39, thereby limiting theinward vmovement of said dogs, the outer edges of which are, at thistime substantially flush with the outer surface of the casing 12.Slightly in the rear of the stop shoulders 41 the dogs 37 are formedwith lateral projections42 having beveled rear faces 44 and front faces43 which are squared off parallel with the front face of the bar 15 andlie slightly in front thereof.

In operation,.as the staple strip is fed forwardly by the feed pawl26,'the legs or prongs of the foremost staple thereof engage the beveledfaces 44 of the projections 42,

thereby forcing the dogs v37 outwardly and permitting said staple topasssaid projections, after which the springs 40 will return the dogs 37 tonormal position, causing the square faces 43 of the projections 42 toengage the rear sides of the legs of the staple, thereby positively andrigidly holding the latter in upright position, and preventing the samefrom being bent around the end of the bar 15 when the plunger 19descends. It will be seen that, in'addition to this function, theprojections 42 will also act as detents to hold the staple strip againstrearward or retrograde movement during the rearward movement of the feedpawl 261' In order to insure the latter operation, particularly afterthe foremost staple has been severed from the strip, each of the dogs 37is ples and which must be cut in order to sever the individual staplesfrom the strips, is relatively narrow, so that the lower, orcutting anddriving end of the plunger 19 may be made of such a wldth that it willreadily pass between the projections 42 on the dogs 37 without engagingor injuring the same and without interfering with their operation.-

In the form of the invention shown in Figs. 6, 7 and 8,'the staplecarrying bar 15 is provided at its forward end, and slightly below itsupper surface, with parallel lat eral slots or grooves 46 in which arelocated dogs 47 pivoted at 51. Said dogs 47 are normally forcedoutwardly by a spring 52 interposed between them and located in atransverse chamber 53 in said bar, the outward movement of said dogsbeing limited by engagement of shoulders 54 thereon with the inner endsof said grooves, said dogs at this time lying with their outer edgessubstantially flush with the lateral faces of the bar. At their forwardends the dogs 47 are formed with outwardly projecting teeth 55 havingbeveled rear faces 56 and square front faces 57 lying slightly in frontof the forward end of the bar 15 and adapted to engage the rear sides ofthe legs of the foremost staple. In the rear of the tooth 55, and spacedtherefrom to correspond with the spacing of the staples on the strip,each dog 47 is provided with a second tooth 58 substantially similar totooth 55. The operation of the teeth 55 and 58 is substantially the sameas that of the teeth 42 and 4:5 in the form of the invention firstdescribed, as will, it is thought, be fully understood'without furtherexplanation.

Having thus described my invention, I claim: 1

1. In a strip staple machine provided with a casing, the combinationwith means for supporting a staple strip and a plunger for severing anddriving the individual staples, of means for feeding said stripcomprising an oscillating plate operated by said plunger, a feed pawlpivoted to said plate, and a spring pressed plunger mounted to slide inthe casing and engaging said pawl and tending to hold the pawl inengagement with the strip.

2. In a strip staple machine, the combination with means for supportinga staple strip and means for severing and driving the individualstaples, of means for feeding said strip comprising a feed pawl having aportion adapted to engage the top of said strip and a beveled lugadapted to engage under the individual staples thereof for holding saidpawl in engagement with said strip during a feeding movement of thepawl.

3. In a strip staple machine, the combination with means for supportinga staple strip and a plunger for severing and driving the individualstaples, of means for feeding said strip comprising an oscillating plateoperated by said plunger, a feed pawl pivoted to said plate and having aportion adapted to engage the top of said strip and a beveled lugadapted to engage under the staples thereof for holding said pawl inengagement with said strip during a feeding movement of the pawl, and aspring pressed plunger engaging said pawl.

4. In a strip staple machine, the combination with means for supportinga staple strip and means for severing and driving the in-- dividualstaples, of means for feeding said strip comprising a pivoted feed pawlhaving a pair of arms provided with means at the under sides of theirforward ends to engage the staple strip and hold it in engagementtherewith during the feeding movement and connected at the upper sidesof their rear ends by a bridge piece, and means engaging said bridgepiece for holding said arms in engagement with said strip.

5. In a strip staple machine, the combination with means for supportinga staple strip and a plunger for severing and driving the individualstaples, of means for feeding said strip comprising an oscillating plateoperated by said plunger, a feed pawl pivoted to said-plate, said pawlhaving a pair of arms provided with means at the under sides of theirforward ends to engage the staple strip and hold it in engagementtherewith during the feeding movement and connected at the upper sidesof their rear ends by a bridge piece, and a spring pressed plungerengaging said bridge piece.

6. In a strip staple machine, the combina tion with means for supportinga staple strip and means for severing and driving the individualstaples, of means for feeding said strip comprising a feed pawl having apair of arms connected at the upper sides of their rear ends by a bridgepiece, said arms at their forward ends engaging the top of said stripand having beveled lugs adapted to engage under the individual staplesthereof for holding said arms in engagement with said strip during thefeeding movementof the pawl.

7. In a strip staple machine, the combination with means for supportinga. staple strip and a plunger for severing and driving the individualstaples, of means for feeding said strip comprising an oscillating plateoperated by said plunger, a feed pawl pivoted to said plate and having apair of arms connected at the upper side of their rear ends by a bridgepiece, said arms at their forward ends engaging the top of said stripand having beveled lugs adapted to engage under the individual staplesthereof for holding said arms in engagement with said strip during thefeeding movement of the pawl, and a spring pressed plunger engaging saidbridge piece.

8. In a strip staple machine, the combination with means for supportinga staple strip and a plunger for severing and driving the individualstaples, of means for feeding said strip, comprising. an oscillatingplate operated by said plunger and having a portion beveled on oppositesides thereof, a feed pawl pivoted to said plate and having a pair ofstrip engaging arms lying respecmay onopposite sides aaaaga a thebeveled portion of said 'platewhereby it is guided laterally; 1

9. 11a "tripfstap'leinachine, the combinati on withf means ,fforsupporting a staple stri'p-a'nd'a': plunger for. sevfring and drivingthe individual staples, means for feeding said strip. comprisingranoscillating plate operated by said plunger. and .having a lower endbeveled on opposite. sides thereof, a feed pawlpivoted to said plate andhaving a pair of arms lying respectively on opposite sides of andengaging the beveled .end of said plate whereby said pawl is guidedlaterally,

nation with means for supporting a staple .strip and a plunger forsevering and drlvwardly in the slot about its pivot to ing theindividual staples, of means for feeding said strip comprising anoscillating plate operated by said plunger and having a beveled lowerend, a feed pawl pivoted to said plate and having a pair of arms lyingrespectively on opposite sides of and engaging the beveled end of saidplate and conneeted at the-upper sides of their rear ends by a bridgepiece, said arms at their forwardends engaging the top of said strip andhaving beveled lugs adapted to engage under the individual staplesthereof for holding said pawl in engagement with said strip during afeeding movement of the pawl, and a spring pressed plunger engag ingsaid bridge piece.

11.- Ina strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a pivotally mounted, laterally movable, rigid dog having a portionadapted to engagea leg of the foremost staple on said strip and holdsaid staple against turning during the severing operation. Y 12. .In astrip staple machine, the combination with means for feeding a staplestrip and means for severing and driving the individual staples, saidmachine having a portion provided with a slot, of a dog pivoted in saidslot andhaving a portion adapted to engage a leg said strip and holdsaid staple against turning during the severing operation, and yieldingmeans tending to move the dog outstaple holding position.

13. In a strip staple machine, the combination with means for feeding astaple strip and mean for severing and driving the individual staples,said machine having a portion provided with a slot, of a dog pivotedengage of the foremost staple on in lsaid slot and laterally movabletherein, said dog having a portion adapted to engage a leg of theforemost staple on said str1pand hold said staple against turning duringthe severing operation, and yielding means tending to move the dog aboutits pivot to and means for severing and driving the individual staples,of a palrof independently pivoted, laterally movable, rigid dogs havingportions adapted to engage the legs of the foremost staple on said stripand hold said staple against turning during the severing operation.

15. In a strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a pair of independently pivoted, rigid dogs having portions adaptedto engage the legs of the foremost staple on said strip and turningduring the severing operation.

16. ,In a strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual. staples,said machine having a portion provided with a pair of oppositelydisposed slots, of dogs pivoted in said slots .re-

spectively and having portions adapted to engage the legs of theforemost staples on said strip and hold said staple againstturning'during the severing operation, and yielding means tending tomove the dogs on their pivots to staple holding position,

17. In a strip staple machine, the combihold saidstaple against nationwith means for feeding a staple strip and means for severing and drivingthe individual staples, of a rigid dog mounted on a fixed pivot andlaterally movable thereon, said dog having a portion adapted to a leg ofthe foremost staple on said strip and hold said staple against turningduring the severing operation.

18. In a strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a pivotally mounted. rigid dog having a portion adapted to engage aleg of the foremost staple on said strip and hold said staple againstturning during the severing operation, and yielding means tending tomove the dog on its pivot to staple holding position.

19. In a strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a pair of pivotally mounted rigid dogs havingportions adapted toengage the legs of the foremost staple on said strip and hold saidstaple against turning during the severing operation, and yielding meanstending to move the dogs to staple holding position.

20. In a strip staple machine, the combination with means for feeding astaple the individual staples,

strip and means for severing of a rigid dog mounted on a fixed pivot andhaving a portion adapted to engage a leg of the foremost staple on saidstaple strip and hold said staple against turning during the severingoperation.

21. In a strip staple machine, the combination with means for feeding astaple- .strip and means for severing and driving the individualstaples, of a dog having a plurality of rigid teeth adapted to engagethe legs of successive staples at the forward end of said strip and holdthe staples against turning during the severing operation.

22. In a strip staple machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a pivoted dog having a portion adapted to engage ale of the foremoststaple on said strip and hold said staple against turning during thesevering operation, yielding means tending to turn the dog on its pivotto staple holding position and means for limiting the movement of saiddog on its pivot.

23. In a staple strip machine, the combination with means for feeding astaple strip and means for severing and driving the individual staples,of a rigid, pivoted dog having a portion adapted to engage a leg of theforemost staple on said strip and hold said staple against turningduring the severing operation, and means for limiting the movement ofsaid dog on its pivot.

24. In a strip staple machine, the combination With means for feeding astaple strip and means for severing and driving the individual staples,said machine having a portion provided with a slot, of a dog pivoted insaid slot and having a portionadapted to engage a leg of the foremoststaple on said strip .and hold said staple against turning during thesevering operation, said dog having a shoulder adapted to engage the endof said slot and limit the movement of said dog on its pivot.

25. In a strip staple machine, the combination with a casing having aslot, means for feeding a staple strip, and means for severing anddriving the individual staples, of'a dog pivoted in said slot and havinga and driving portion adapted to engage a leg of the foremost staple onsaid strlp and hold said Staple against turning during the severingoperation, and yielding means tending. to move the dog on its pivot tostaple holding position.

26. In a strip staple machine, the combination with a casing having aslot in its side Wall, means for feeding a staple strip, and means forsevering and driving the individual staples, of a dog pivotedin saidslot and laterally movable therein, said dog having a portion adapted toengage a leg of the foremost staple on said strip and hold said stapleagainst turning during the severing operation, and yielding meanstending to move the dog on its pivot to staple hold ing position.

27. In a strip staple machine, the combination with a casing,havingoppositely disposed slots in its walls, means for feeding a staplestrip, and means for severing and driving the individual staples, ofdogs pivoted in said slots respectively and having portions adapted toengage the legs of the foremost staple on said strip and hold saidstaple against turning during the severing operation, and yielding meanstending to move the dogs on their pivots to staple holding position.

28.In a. strip staple machine, the combination with a casing, having aslot, means for feeding a staple strip, and means for severing anddriving the individual staples, of a dog pivoted in said slot and havinga portion adapted to engage a leg of the foremost staple on said stripandhold said staple against turning during the severing operation, saiddog having a shoulder adapted to engage the end of said slot and limitthe movement of said dog on its pivot.

29. In a strip staple machine, the combination With a casing, having aslot, means

